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Want to be Pregnant? Remember Vitamins are Important

By Michael McBurney

When people think about vitamins and dietary supplementation, the tendency is to think about prolonging life for older adults - reducing risk of cancer and cardiovascular disease later in life. Vitamins are also important to conceive and carry a baby to full term.

A new study finds women with high serum vitamin D concentrations (> 75 nmol/L) undergoing in vitro fertilization (IVF) have significantly higher chances of becoming pregnant . Paffoni and colleagues investigated IVF rates among healthy women (18-42y) with normal body weight (BMI 18-25). The women who had been referred to an infertility unit had serum 25(OH)D3 concentrations measured and correlated with fertilization rates. Women with the highest vitamin D levels (group mean = 73) had pregnancy rates 1.85 times higher than those below 50 nmol/L ( group mean = 35). The authors write, “Overall, we believe that it can be concluded that vitamin D insufficiency negatively affects clinical pregnancy in women undergoing IVF.”

The association reported for vitamin D and fertility is observational. It does not confirm cause and effect. The finds are very relevant to couples wanting to have children. 99% of US women do not consume the Estimated Average Requirement (EAR) for vitamin D from their diet.

The scientific literature is rich with in vitro and animal studies demonstrating a cause and effect role of vitamins D, C and E on fertility and pregnancy. Emerging evidence is linking suboptimal vitamin status with in vitro fertilization rates and pregnancy outcomes. Want to have a baby? Remember vitamins are essential for life.

A few thoughts: Vitamin D status is influenced by many things…sunlight exposure (and all of the things that influence whether or not one chooses to go in the sun), supplements, tanning, season, dietary intake but also perhaps most importantly age, obesity, smoking and perhaps inflammation. Which of these influence both status AND IVF rates? Without getting too much into detail their approach to selecting confounders was less than ideal and did not consider all the possible confounders that I would be concerned by…no mention of smoking for example or inclusion of age or season in the final model.

In their methods they mentioned analyzing by two groups (cutoff of 20ng) but in the results they break it into 3 groups, suggesting that there was some post-hoc analysis (fishing…?)